OpenCV笔记12：霍夫变换检测圆

#include "stdafx.h"

#include <cv.h>

#include <highgui.h>

#include <math.h>

int main(int argc, char** argv)

{

IplImage* img;

if( argc == 2 && (img=cvLoadImage(argv[1], 1))!= 0)

{

IplImage* gray = cvCreateImage( cvGetSize(img), 8, 1 );

CvMemStorage* storage = cvCreateMemStorage(0);

cvCvtColor( img, gray, CV_BGR2GRAY );

cvSmooth( gray, gray, CV_GAUSSIAN, 9, 9 ); // smooth it, otherwise a lot of false circles may be detected

CvSeq* circles = cvHoughCircles( gray, storage, CV_HOUGH_GRADIENT, 2, gray->height/4, 200, 100 );

int i;

for( i = 0; i < circles->total; i++ )

{

float* p = (float*)cvGetSeqElem( circles, i );

cvCircle( img, cvPoint(cvRound(p[0]),cvRound(p[1])), 3, CV_RGB(0,255,0), -1, 8, 0 );

cvCircle( img, cvPoint(cvRound(p[0]),cvRound(p[1])), cvRound(p[2]), CV_RGB(255,0,0), 3, 8, 0 );

}

cvNamedWindow( "circles", 1 );

cvShowImage( "circles", img );

cvWaitKey(0);

}

return 0;

}